Recent years have seen active development of active-matrix display devices using a liquid crystal panel or an electroluminescence element (hereafter referred to as an organic EL element). In particular, as image display devices using current-driven light-emitting elements, organic EL displays using organic EL elements have the advantage of excellent viewing angle characteristics and low power consumption, and are thus attracting attention as candidates for next-generation flat-panel displays (FPDs).
In the aforementioned active-matrix display device, images are displayed by selecting two-dimensionally arranged pixel circuits on a row basis, and writing a voltage corresponding to display data into the selected pixel circuits via a signal line. In order to select pixel circuits on a row basis, a shift register is used which sequentially shifts the output signal outputted to a scanning line, based on a clock signal from a scanning line driving circuit.
Furthermore, a shift register such as that described above uses a buffer circuit in which transistors are connected in series via an output terminal (see Patent Literature (PTL) 1, for example).